src/ATC/tower.cxx

   1 // FGTower - a class to provide tower control at towered airports.
   2 //
   3 // Written by David Luff, started March 2002.
   4 //
   5 // Copyright (C) 2002  David C. Luff - david.luff@nottingham.ac.uk
   6 //
   7 // This program is free software; you can redistribute it and/or
   8 // modify it under the terms of the GNU General Public License as
   9 // published by the Free Software Foundation; either version 2 of the
  10 // License, or (at your option) any later version.
  11 //
  12 // This program is distributed in the hope that it will be useful, but
  13 // WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15 // General Public License for more details.
  16 //
  17 // You should have received a copy of the GNU General Public License
  18 // along with this program; if not, write to the Free Software
  19 // Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20
  21 #include <Main/globals.hxx>
  22 #include <Airports/runways.hxx>
  23 #include <simgear/math/sg_geodesy.hxx>
  24 #include <simgear/debug/logstream.hxx>
  25
  26 #include "tower.hxx"
  27 #include "ATCdisplay.hxx"
  28 #include "ATCmgr.hxx"
  29 #include "ATCutils.hxx"
  30 #include "commlist.hxx"
  31 #include "AILocalTraffic.hxx"
  32
  33 SG_USING_STD(cout);
  34
  35 // TowerPlaneRec
  36
  37 TowerPlaneRec::TowerPlaneRec() :
  38 clearedToLand(false),
  39 clearedToLineUp(false),
  40 clearedToTakeOff(false),
  41 holdShortReported(false),
  42 downwindReported(false),
  43 longFinalReported(false),
  44 longFinalAcknowledged(false),
  45 finalReported(false),
  46 finalAcknowledged(false),
  47 onRwy(false),
  48 nextOnRwy(false),
  49 opType(TTT_UNKNOWN),
  50 leg(LEG_UNKNOWN),
  51 landingType(AIP_LT_UNKNOWN),
  52 isUser(false)
  53 {
  54         plane.callsign = "UNKNOWN";
  55 }
  56
  57 TowerPlaneRec::TowerPlaneRec(PlaneRec p) :
  58 clearedToLand(false),
  59 clearedToLineUp(false),
  60 clearedToTakeOff(false),
  61 holdShortReported(false),
  62 downwindReported(false),
  63 longFinalReported(false),
  64 longFinalAcknowledged(false),
  65 finalReported(false),
  66 finalAcknowledged(false),
  67 onRwy(false),
  68 nextOnRwy(false),
  69 opType(TTT_UNKNOWN),
  70 leg(LEG_UNKNOWN),
  71 landingType(AIP_LT_UNKNOWN),
  72 isUser(false)
  73 {
  74         plane = p;
  75 }
  76
  77 TowerPlaneRec::TowerPlaneRec(Point3D pt) :
  78 clearedToLand(false),
  79 clearedToLineUp(false),
  80 clearedToTakeOff(false),
  81 holdShortReported(false),
  82 downwindReported(false),
  83 longFinalReported(false),
  84 longFinalAcknowledged(false),
  85 finalReported(false),
  86 finalAcknowledged(false),
  87 onRwy(false),
  88 nextOnRwy(false),
  89 opType(TTT_UNKNOWN),
  90 leg(LEG_UNKNOWN),
  91 landingType(AIP_LT_UNKNOWN),
  92 isUser(false)
  93 {
  94         plane.callsign = "UNKNOWN";
  95         pos = pt;
  96 }
  97
  98 TowerPlaneRec::TowerPlaneRec(PlaneRec p, Point3D pt) :
  99 clearedToLand(false),
 100 clearedToLineUp(false),
 101 clearedToTakeOff(false),
 102 holdShortReported(false),
 103 downwindReported(false),
 104 longFinalReported(false),
 105 longFinalAcknowledged(false),
 106 finalReported(false),
 107 finalAcknowledged(false),
 108 onRwy(false),
 109 nextOnRwy(false),
 110 opType(TTT_UNKNOWN),
 111 leg(LEG_UNKNOWN),
 112 landingType(AIP_LT_UNKNOWN),
 113 isUser(false)
 114 {
 115         plane = p;
 116         pos = pt;
 117 }
 118
 119
 120 // FGTower
 121
 122 FGTower::FGTower() {
 123         ATCmgr = globals->get_ATC_mgr();
 124
 125         // Init the property nodes - TODO - need to make sure we're getting surface winds.
 126         wind_from_hdg = fgGetNode("/environment/wind-from-heading-deg", true);
 127         wind_speed_knots = fgGetNode("/environment/wind-speed-kt", true);
 128
 129         update_count = 0;
 130         update_count_max = 15;
 131
 132         holdListItr = holdList.begin();
 133         appListItr = appList.begin();
 134         depListItr = depList.begin();
 135         rwyListItr = rwyList.begin();
 136         circuitListItr = circuitList.begin();
 137         trafficListItr = trafficList.begin();
 138
 139         freqClear = true;
 140
 141         timeSinceLastDeparture = 9999;
 142         departed = false;
 143 }
 144
 145 FGTower::~FGTower() {
 146         if(!separateGround) {
 147                 delete ground;
 148         }
 149 }
 150
 151 void FGTower::Init() {
 152     display = false;
 153
 154         // Pointers to user's position
 155         user_lon_node = fgGetNode("/position/longitude-deg", true);
 156         user_lat_node = fgGetNode("/position/latitude-deg", true);
 157         user_elev_node = fgGetNode("/position/altitude-ft", true);
 158         user_hdg_node = fgGetNode("/orientation/heading-deg", true);
 159
 160         // Need some way to initialise rwyOccupied flag correctly if the user is on the runway and to know its the user.
 161         // I'll punt the startup issue for now though!!!
 162         rwyOccupied = false;
 163
 164         // Setup the ground control at this airport
 165         AirportATC a;
 166         //cout << "Tower ident = " << ident << '\n';
 167         if(ATCmgr->GetAirportATCDetails(ident, &a)) {
 168                 if(a.ground_freq) {             // Ground control
 169                         ground = (FGGround*)ATCmgr->GetATCPointer(ident, GROUND);
 170                         separateGround = true;
 171                         if(ground == NULL) {
 172                                 // Something has gone wrong :-(
 173                                 SG_LOG(SG_ATC, SG_WARN, "ERROR - ground has frequency but can't get ground pointer :-(");
 174                                 ground = new FGGround(ident);
 175                                 separateGround = false;
 176                                 ground->Init();
 177                                 if(display) {
 178                                         ground->SetDisplay();
 179                                 } else {
 180                                         ground->SetNoDisplay();
 181                                 }
 182                         }
 183                 } else {
 184                         // Initialise ground anyway to do the shortest path stuff!
 185                         // Note that we're now responsible for updating and deleting this - NOT the ATCMgr.
 186                         ground = new FGGround(ident);
 187                         separateGround = false;
 188                         ground->Init();
 189                         if(display) {
 190                                 ground->SetDisplay();
 191                         } else {
 192                                 ground->SetNoDisplay();
 193                         }
 194                 }
 195         } else {
 196                 SG_LOG(SG_ATC, SG_ALERT, "Unable to find airport details for " << ident << " in FGTower::Init()");
 197                 // Initialise ground anyway to avoid segfault later
 198                 ground = new FGGround(ident);
 199                 separateGround = false;
 200                 ground->Init();
 201                 if(display) {
 202                         ground->SetDisplay();
 203                 } else {
 204                         ground->SetNoDisplay();
 205                 }
 206         }
 207
 208         // Get the airport elevation
 209         aptElev = dclGetAirportElev(ident.c_str()) * SG_FEET_TO_METER;
 210
 211         DoRwyDetails();
 212
 213         // FIXME - this currently assumes use of the active rwy by the user.
 214         rwyOccupied = OnAnyRunway(Point3D(user_lon_node->getDoubleValue(), user_lat_node->getDoubleValue(), 0.0));
 215         if(rwyOccupied) {
 216                 // Assume the user is started at the threshold ready to take-off
 217                 TowerPlaneRec* t = new TowerPlaneRec;
 218                 t->plane.callsign = "Charlie Foxtrot Sierra";   // C-FGFS !!! - fixme - this is a bit hardwired
 219                 t->plane.type = GA_SINGLE;
 220                 t->opType = TTT_UNKNOWN;        // We don't know if the user wants to do circuits or a departure...
 221                 t->landingType = AIP_LT_UNKNOWN;
 222                 t->leg = TAKEOFF_ROLL;
 223                 t->isUser = true;
 224                 t->planePtr = NULL;
 225                 t->clearedToTakeOff = true;
 226                 rwyList.push_back(t);
 227                 departed = false;
 228         }
 229 }
 230
 231 void FGTower::Update(double dt) {
 232         //cout << "T" << endl;
 233         // Each time step, what do we need to do?
 234         // We need to go through the list of outstanding requests and acknowedgements
 235         // and process at least one of them.
 236         // We need to go through the list of planes under our control and check if
 237         // any need to be addressed.
 238         // We need to check for planes not under our control coming within our
 239         // control area and address if necessary.
 240
 241         // TODO - a lot of the below probably doesn't need to be called every frame and should be staggered.
 242
 243         // Sort the arriving planes
 244
 245         /*
 246         if(ident == "KEMT") {
 247                 cout << update_count << "\ttL: " << trafficList.size() << "  cL: " << circuitList.size() << "  hL: " << holdList.size() << "  aL: " << appList.size() << '\n';
 248         }
 249         */
 250
 251         if(departed != false) {
 252                 timeSinceLastDeparture += dt;
 253                 //if(ident == "KEMT")
 254                 //      cout << "  dt = " << dt << "  timeSinceLastDeparture = " << timeSinceLastDeparture << '\n';
 255         }
 256
 257         if(respond) {
 258                 if(!responseReqd) SG_LOG(SG_ATC, SG_ALERT, "ERROR - respond is true and responseReqd is false in FGTower::Update(...)");
 259                 Respond();
 260                 respond = false;
 261                 responseReqd = false;
 262         }
 263
 264         // Calculate the eta of each plane to the threshold.
 265         // For ground traffic this is the fastest they can get there.
 266         // For air traffic this is the middle approximation.
 267         if(update_count == 1) {
 268                 doThresholdETACalc();
 269         }
 270
 271         // Order the list of traffic as per expected threshold use and flag any conflicts
 272         if(update_count == 2) {
 273                 //bool conflicts = doThresholdUseOrder();
 274                 doThresholdUseOrder();
 275         }
 276
 277         // sortConficts() !!!
 278
 279         if(update_count == 4) {
 280                 CheckHoldList(dt);
 281         }
 282
 283         // Uggh - HACK - why have we got rwyOccupied - wouldn't simply testing rwyList.size() do?
 284         if(rwyList.size()) {
 285                 rwyOccupied = true;
 286         } else {
 287                 rwyOccupied = false;
 288         }
 289
 290         if(update_count == 5 && rwyOccupied) {
 291                 CheckRunwayList(dt);
 292         }
 293
 294         if(update_count == 6) {
 295                 CheckCircuitList(dt);
 296         }
 297
 298         if(update_count == 7) {
 299                 CheckApproachList(dt);
 300         }
 301
 302         // TODO - do one plane from the departure list and set departed = false when out of consideration
 303
 304         //doCommunication();
 305
 306         if(!separateGround) {
 307                 // The display stuff might have to get more clever than this when not separate
 308                 // since the tower and ground might try communicating simultaneously even though
 309                 // they're mean't to be the same contoller/frequency!!
 310                 if(display) {
 311                         ground->SetDisplay();
 312                 } else {
 313                         ground->SetNoDisplay();
 314                 }
 315                 ground->Update(dt);
 316         }
 317
 318         ++update_count;
 319         // How big should ii get - ie how long should the update cycle interval stretch?
 320         if(update_count >= update_count_max) {
 321                 update_count = 0;
 322         }
 323
 324         // Call the base class update for the response time handling.
 325         FGATC::Update(dt);
 326
 327         if(ident == "KEMT") {
 328                 // For AI debugging convienience - may be removed
 329                 Point3D user_pos;
 330                 user_pos.setlon(user_lon_node->getDoubleValue());
 331                 user_pos.setlat(user_lat_node->getDoubleValue());
 332                 user_pos.setelev(user_elev_node->getDoubleValue());
 333                 Point3D user_ortho_pos = ortho.ConvertToLocal(user_pos);
 334                 fgSetDouble("/AI/user/ortho-x", user_ortho_pos.x());
 335                 fgSetDouble("/AI/user/ortho-y", user_ortho_pos.y());
 336                 fgSetDouble("/AI/user/elev", user_elev_node->getDoubleValue());
 337         }
 338
 339         //cout << "Done T" << endl;
 340 }
 341
 342 void FGTower::Respond() {
 343         //cout << "Entering Respond..." << endl;
 344         TowerPlaneRec* t = FindPlane(responseID);
 345         if(t) {
 346                 // This will grow!!!
 347                 if(t->downwindReported) {
 348                         t->downwindReported = false;
 349                         int i = 1;
 350                         for(tower_plane_rec_list_iterator twrItr = circuitList.begin(); twrItr != circuitList.end(); twrItr++) {
 351                                 if((*twrItr)->plane.callsign == responseID) break;
 352                                 ++i;
 353                         }
 354                         string trns = "Number ";
 355                         trns += ConvertNumToSpokenDigits(i);
 356                         trns += " ";
 357                         trns += t->plane.callsign;
 358                         if(display) {
 359                                 globals->get_ATC_display()->RegisterSingleMessage(trns, 0);
 360                         }
 361                         if(t->isUser && t->opType == TTT_UNKNOWN) {
 362                                 t->opType = CIRCUIT;
 363                         }
 364                 } else if(t->holdShortReported) {
 365                         if(t->nextOnRwy) {
 366                                 if(rwyOccupied) {       // TODO - ought to add a sanity check that it isn't this plane only on the runway (even though it shouldn't be!!)
 367                                         // Do nothing for now - consider acknowloging hold short eventually
 368                                 } else {
 369                                         ClearHoldingPlane(t);
 370                                         t->leg = TAKEOFF_ROLL;
 371                                         rwyList.push_back(t);
 372                                         rwyOccupied = true;
 373                                         // WARNING - WE ARE ASSUMING ONLY ONE PLANE REPORTING HOLD AT A TIME BELOW
 374                                         // FIXME TODO - FIX THIS!!!
 375                                         if(holdList.size()) {
 376                                                 if(holdListItr == holdList.end()) {
 377                                                         holdListItr = holdList.begin();
 378                                                 }
 379                                                 holdList.erase(holdListItr);
 380                                                 holdListItr = holdList.begin();
 381                                         }
 382                                 }
 383                         } else {
 384                                 // Tell him to hold and what position he is.
 385                                 // Not currently sure under which circumstances we do or don't bother transmitting this.
 386                                 string trns = t->plane.callsign;
 387                                 trns += " hold position";
 388                                 if(display) {
 389                                         globals->get_ATC_display()->RegisterSingleMessage(trns, 0);
 390                                 }
 391                                 // TODO - add some idea of what traffic is blocking him.
 392                         }
 393                         t->holdShortReported = false;
 394                 }
 395         }
 396         freqClear = true;       // FIXME - set this to come true after enough time to render the message
 397         //cout << "Done Respond" << endl;
 398 }
 399
 400 // Currently this assumes we *are* next on the runway and doesn't check for planes about to land -
 401 // this should be done prior to calling this function.
 402 void FGTower::ClearHoldingPlane(TowerPlaneRec* t) {
 403         //cout << "Entering ClearHoldingPlane..." << endl;
 404         // Lets Roll !!!!
 405         string trns = t->plane.callsign;
 406         //if(departed plane < some threshold in time away) {
 407         if(0) {         // FIXME
 408         //if(timeSinceLastDeparture <= 60.0 && departed == true) {
 409                 trns += " line up";
 410                 t->clearedToLineUp = true;
 411                 t->planePtr->RegisterTransmission(3);   // cleared to line-up
 412         //} else if(arriving plane < some threshold away) {
 413         } else if(GetTrafficETA(2) < 150.0 && (timeSinceLastDeparture > 60.0 || departed == false)) {   // Hack - hardwired time
 414                 trns += " cleared immediate take-off";
 415                 if(trafficList.size()) {
 416                         tower_plane_rec_list_iterator trfcItr = trafficList.begin();
 417                         trfcItr++;      // At the moment the holding plane should be first in trafficList.
 418                         // Note though that this will break if holding planes aren't put in trafficList in the future.
 419                         TowerPlaneRec* trfc = *trfcItr;
 420                         trns += "... traffic is";
 421                         switch(trfc->plane.type) {
 422                         case UNKNOWN:
 423                                 break;
 424                         case GA_SINGLE:
 425                                 trns += " a Cessna";    // TODO - add ability to specify actual plane type somewhere
 426                                 break;
 427                         case GA_HP_SINGLE:
 428                                 trns += " a Piper";
 429                                 break;
 430                         case GA_TWIN:
 431                                 trns += " a King-air";
 432                                 break;
 433                         case GA_JET:
 434                                 trns += " a Learjet";
 435                                 break;
 436                         case MEDIUM:
 437                                 trns += " a Regional";
 438                                 break;
 439                         case HEAVY:
 440                                 trns += " a Heavy";
 441                                 break;
 442                         case MIL_JET:
 443                                 trns += " Military";
 444                                 break;
 445                         }
 446                         //if(trfc->opType == STRAIGHT_IN || trfc->opType == TTT_UNKNOWN) {
 447                         if(trfc->opType == STRAIGHT_IN) {
 448                                 double miles_out = CalcDistOutMiles(trfc);
 449                                 if(miles_out < 2) {
 450                                         trns += " on final";
 451                                 } else {
 452                                         trns += " on ";
 453                                         trns += ConvertNumToSpokenDigits((int)miles_out);
 454                                         trns += " mile final";
 455                                 }
 456                         } else if(trfc->opType == CIRCUIT) {
 457                                 //cout << "Getting leg of " << trfc->plane.callsign << '\n';
 458                                 switch(trfc->leg) {
 459                                 case FINAL:
 460                                         trns += " on final";
 461                                         break;
 462                                 case TURN4:
 463                                         trns += " turning final";
 464                                         break;
 465                                 case BASE:
 466                                         trns += " on base";
 467                                         break;
 468                                 case TURN3:
 469                                         trns += " turning base";
 470                                         break;
 471                                 case DOWNWIND:
 472                                         trns += " in circuit";  // At the moment the user plane is generally flagged as unknown opType when downwind incase its a downwind departure which means we won't get here.
 473                                         break;
 474                                 // And to eliminate compiler warnings...
 475                                 case TAKEOFF_ROLL: break;
 476                                 case CLIMBOUT:     break;
 477                                 case TURN1:        break;
 478                                 case CROSSWIND:    break;
 479                                 case TURN2:        break;
 480                                 case LANDING_ROLL: break;
 481                                 case LEG_UNKNOWN:  break;
 482                                 }
 483                         }
 484                 } else {
 485                         // By definition there should be some arriving traffic if we're cleared for immediate takeoff
 486                         SG_LOG(SG_ATC, SG_WARN, "Warning: Departing traffic cleared for *immediate* take-off despite no arriving traffic in FGTower");
 487                 }
 488                 t->clearedToTakeOff = true;
 489                 t->planePtr->RegisterTransmission(4);   // cleared to take-off - TODO differentiate between immediate and normal take-off
 490                 departed = false;
 491                 timeSinceLastDeparture = 0.0;
 492         } else {
 493         //} else if(timeSinceLastDeparture > 60.0 || departed == false) {       // Hack - test for timeSinceLastDeparture should be in lineup block eventually
 494                 trns += " cleared for take-off";
 495                 // TODO - add traffic is... ?
 496                 t->clearedToTakeOff = true;
 497                 t->planePtr->RegisterTransmission(4);   // cleared to take-off
 498                 departed = false;
 499                 timeSinceLastDeparture = 0.0;
 500         }
 501         if(display) {
 502                 globals->get_ATC_display()->RegisterSingleMessage(trns, 0);
 503         }
 504         //cout << "Done ClearHoldingPlane " << endl;
 505 }
 506
 507 // Do one plane from the hold list
 508 void FGTower::CheckHoldList(double dt) {
 509         //cout << "Entering CheckHoldList..." << endl;
 510         if(holdList.size()) {
 511                 //cout << "*holdListItr = " << *holdListItr << endl;
 512                 if(holdListItr == holdList.end()) {
 513                         holdListItr = holdList.begin();
 514                 }
 515                 //cout << "*holdListItr = " << *holdListItr << endl;
 516                 //Process(*holdListItr);
 517                 TowerPlaneRec* t = *holdListItr;
 518                 //cout << "t = " << t << endl;
 519                 if(t->holdShortReported) {
 520                         // NO-OP - leave it to the response handler.
 521                 } else {        // not responding to report, but still need to clear if clear
 522                         if(t->nextOnRwy) {
 523                                 //cout << "departed = " << departed << '\n';
 524                                 //cout << "timeSinceLastDeparture = " << timeSinceLastDeparture << '\n';
 525                                 if(rwyOccupied) {
 526                                         // Do nothing
 527                                 } else if(timeSinceLastDeparture <= 60.0 && departed == true) {
 528                                         // Do nothing - this is a bit of a hack - should maybe do line up be ready here
 529                                 } else {
 530                                         ClearHoldingPlane(t);
 531                                         t->leg = TAKEOFF_ROLL;
 532                                         rwyList.push_back(t);
 533                                         rwyOccupied = true;
 534                                         holdList.erase(holdListItr);
 535                                         holdListItr = holdList.begin();
 536                                 }
 537                         }
 538                         // TODO - rationalise the considerable code duplication above!
 539                 }
 540                 ++holdListItr;
 541         }
 542         //cout << "Done CheckHoldList" << endl;
 543 }
 544
 545 // do the ciruit list
 546 void FGTower::CheckCircuitList(double dt) {
 547         //cout << "Entering CheckCircuitList..." << endl;
 548         // Clear the constraints - we recalculate here.
 549         base_leg_pos = 0.0;
 550         downwind_leg_pos = 0.0;
 551         crosswind_leg_pos = 0.0;
 552
 553         if(circuitList.size()) {        // Do one plane from the circuit
 554                 if(circuitListItr == circuitList.end()) {
 555                         circuitListItr = circuitList.begin();
 556                 }
 557                 TowerPlaneRec* t = *circuitListItr;
 558                 if(t->isUser) {
 559                         t->pos.setlon(user_lon_node->getDoubleValue());
 560                         t->pos.setlat(user_lat_node->getDoubleValue());
 561                         t->pos.setelev(user_elev_node->getDoubleValue());
 562                 } else {
 563                         t->pos = t->planePtr->GetPos();         // We should probably only set the pos's on one walk through the traffic list in the update function, to save a few CPU should we end up duplicating this.
 564                         t->landingType = t->planePtr->GetLandingOption();
 565                         //cout << "AI plane landing option is " << t->landingType << '\n';
 566                 }
 567                 Point3D tortho = ortho.ConvertToLocal(t->pos);
 568                 if(t->isUser) {
 569                         // Need to figure out which leg he's on
 570                         //cout << "rwy.hdg = " << rwy.hdg << " user hdg = " << user_hdg_node->getDoubleValue();
 571                         double ho = GetAngleDiff_deg(user_hdg_node->getDoubleValue(), rwy.hdg);
 572                         //cout << " ho = " << ho << " abs(ho = " << abs(ho) << '\n';
 573                         // TODO FIXME - get the wind and convert this to track, or otherwise use track somehow!!!
 574                         // If it's gusty might need to filter the value, although we are leaving 30 degrees each way leeway!
 575                         if(abs(ho) < 30) {
 576                                 // could be either takeoff, climbout or landing - check orthopos.y
 577                                 //cout << "tortho.y = " << tortho.y() << '\n';
 578                                 if((tortho.y() < 0) || (t->leg == TURN4) || (t->leg == FINAL)) {
 579                                         t->leg = FINAL;
 580                                         //cout << "Final\n";
 581                                 } else {
 582                                         t->leg = CLIMBOUT;      // TODO - check elev wrt. apt elev to differentiate takeoff roll and climbout
 583                                         //cout << "Climbout\n";
 584                                         // If it's the user we may be unsure of his/her intentions.
 585                                         // (Hopefully the AI planes won't try confusing the sim!!!)
 586                                         if(t->opType == TTT_UNKNOWN) {
 587                                                 if(tortho.y() > 5000) {
 588                                                         // 5 km out from threshold - assume it's a departure
 589                                                         t->opType = OUTBOUND;   // TODO - could check if the user has climbed significantly above circuit altitude as well.
 590                                                         // Since we are unknown operation we should be in depList already.
 591                                                         circuitList.erase(circuitListItr);
 592                                                         RemoveFromTrafficList(t->plane.callsign);
 593                                                         circuitListItr = circuitList.begin();
 594                                                 }
 595                                         } else if(t->opType == CIRCUIT) {
 596                                                 if(tortho.y() > 10000) {
 597                                                         // 10 km out - assume the user has abandoned the circuit!!
 598                                                         t->opType = OUTBOUND;
 599                                                         depList.push_back(t);
 600                                                         circuitList.erase(circuitListItr);
 601                                                         circuitListItr = circuitList.begin();
 602                                                 }
 603                                         }
 604                                 }
 605                         } else if(abs(ho) < 60) {
 606                                 // turn1 or turn 4
 607                                 // TODO - either fix or doublecheck this hack by looking at heading and pattern direction
 608                                 if((t->leg == CLIMBOUT) || (t->leg == TURN1)) {
 609                                         t->leg = TURN1;
 610                                         //cout << "Turn1\n";
 611                                 } else {
 612                                         t->leg = TURN4;
 613                                         //cout << "Turn4\n";
 614                                 }
 615                         } else if(abs(ho) < 120) {
 616                                 // crosswind or base
 617                                 // TODO - either fix or doublecheck this hack by looking at heading and pattern direction
 618                                 if((t->leg == TURN1) || (t->leg == CROSSWIND)) {
 619                                         t->leg = CROSSWIND;
 620                                         //cout << "Crosswind\n";
 621                                 } else {
 622                                         t->leg = BASE;
 623                                         //cout << "Base\n";
 624                                 }
 625                         } else if(abs(ho) < 150) {
 626                                 // turn2 or turn 3
 627                                 // TODO - either fix or doublecheck this hack by looking at heading and pattern direction
 628                                 if((t->leg == CROSSWIND) || (t->leg == TURN2)) {
 629                                         t->leg = TURN2;
 630                                         //cout << "Turn2\n";
 631                                 } else {
 632                                         t->leg = TURN3;
 633                                         // Probably safe now to assume the user is flying a circuit
 634                                         t->opType = CIRCUIT;
 635                                         //cout << "Turn3\n";
 636                                 }
 637                         } else {
 638                                 // downwind
 639                                 t->leg = DOWNWIND;
 640                                 //cout << "Downwind\n";
 641                         }
 642                         if(t->leg == FINAL) {
 643                                 if(OnActiveRunway(t->pos)) {
 644                                         t->leg = LANDING_ROLL;
 645                                 }
 646                         }
 647                 } else {
 648                         t->leg = t->planePtr->GetLeg();
 649                 }
 650
 651                 // Set the constraints IF this is the first plane in the circuit
 652                 // TODO - at the moment we're constraining plane 2 based on plane 1 - this won't (or might not) work for 3 planes in the circuit!!
 653                 if(circuitListItr == circuitList.begin()) {
 654                         switch(t->leg) {
 655                         case FINAL:
 656                                 // Base leg must be at least as far out as the plane is - actually possibly not necessary for separation, but we'll use that for now.
 657                                 base_leg_pos = tortho.y();
 658                                 //cout << "base_leg_pos = " << base_leg_pos << '\n';
 659                                 break;
 660                         case TURN4:
 661                                 // Fall through to base
 662                         case BASE:
 663                                 base_leg_pos = tortho.y();
 664                                 //cout << "base_leg_pos = " << base_leg_pos << '\n';
 665                                 break;
 666                         case TURN3:
 667                                 // Fall through to downwind
 668                         case DOWNWIND:
 669                                 // Only have the downwind leg pos as turn-to-base constraint if more negative than we already have.
 670                                 base_leg_pos = (tortho.y() < base_leg_pos ? tortho.y() : base_leg_pos);
 671                                 //cout << "base_leg_pos = " << base_leg_pos;
 672                                 downwind_leg_pos = tortho.x();          // Assume that a following plane can simply be constrained by the immediately in front downwind plane
 673                                 //cout << " downwind_leg_pos = " << downwind_leg_pos << '\n';
 674                                 break;
 675                         case TURN2:
 676                                 // Fall through to crosswind
 677                         case CROSSWIND:
 678                                 crosswind_leg_pos = tortho.y();
 679                                 //cout << "crosswind_leg_pos = " << crosswind_leg_pos << '\n';
 680                                 break;
 681                         case TURN1:
 682                                 // Fall through to climbout
 683                         case CLIMBOUT:
 684                                 // Only use current by constraint as largest
 685                                 crosswind_leg_pos = (tortho.y() > crosswind_leg_pos ? tortho.y() : crosswind_leg_pos);
 686                                 //cout << "crosswind_leg_pos = " << crosswind_leg_pos << '\n';
 687                                 break;
 688                         case TAKEOFF_ROLL:
 689                                 break;
 690                         case LEG_UNKNOWN:
 691                                 break;
 692                         case LANDING_ROLL:
 693                                 break;
 694                         default:
 695                                 break;
 696                         }
 697                 }
 698
 699                 if(t->leg == FINAL) {
 700                         if(t->landingType == FULL_STOP) t->opType = INBOUND;
 701                 } else if(t->leg == LANDING_ROLL) {
 702                         rwyList.push_front(t);
 703                         RemoveFromTrafficList(t->plane.callsign);
 704                         if(t->isUser) {
 705                                 t->opType = TTT_UNKNOWN;
 706                         }       // TODO - allow the user to specify opType via ATC menu
 707                         circuitListItr = circuitList.erase(circuitListItr);
 708                         if(circuitListItr == circuitList.end() ) {
 709                                 circuitListItr = circuitList.begin();
 710                         }
 711                 }
 712                 ++circuitListItr;
 713         }
 714         //cout << "Done CheckCircuitList" << endl;
 715 }
 716
 717 // Do the runway list - we'll do the whole runway list since it's important and there'll never be many planes on the rwy at once!!
 718 // FIXME - at the moment it looks like we're only doing the first plane from the rwy list.
 719 // (However, at the moment there should only be one airplane on the rwy at once, until we
 720 // start allowing planes to line up whilst previous arrival clears the rwy.)
 721 void FGTower::CheckRunwayList(double dt) {
 722         //cout << "Entering CheckRunwayList..." << endl;
 723         if(rwyOccupied) {
 724                 if(!rwyList.size()) {
 725                         rwyOccupied = false;
 726                 } else {
 727                         rwyListItr = rwyList.begin();
 728                         TowerPlaneRec* t = *rwyListItr;
 729                         if(t->isUser) {
 730                                 t->pos.setlon(user_lon_node->getDoubleValue());
 731                                 t->pos.setlat(user_lat_node->getDoubleValue());
 732                                 t->pos.setelev(user_elev_node->getDoubleValue());
 733                         } else {
 734                                 t->pos = t->planePtr->GetPos();         // We should probably only set the pos's on one walk through the traffic list in the update function, to save a few CPU should we end up duplicating this.
 735                         }
 736                         bool on_rwy = OnActiveRunway(t->pos);
 737                         if(!on_rwy) {
 738                                 if((t->opType == INBOUND) || (t->opType == STRAIGHT_IN)) {
 739                                         rwyList.pop_front();
 740                                         delete t;
 741                                         // TODO - tell it to taxi / contact ground / don't delete it etc!
 742                                 } else if(t->opType == OUTBOUND) {
 743                                         depList.push_back(t);
 744                                         rwyList.pop_front();
 745                                         departed = true;
 746                                         timeSinceLastDeparture = 0.0;
 747                                 } else if(t->opType == CIRCUIT) {
 748                                         circuitList.push_back(t);
 749                                         AddToTrafficList(t);
 750                                         rwyList.pop_front();
 751                                         departed = true;
 752                                         timeSinceLastDeparture = 0.0;
 753                                 } else if(t->opType == TTT_UNKNOWN) {
 754                                         depList.push_back(t);
 755                                         circuitList.push_back(t);
 756                                         AddToTrafficList(t);
 757                                         rwyList.pop_front();
 758                                         departed = true;
 759                                         timeSinceLastDeparture = 0.0;   // TODO - we need to take into account that the user might taxi-in when flagged opType UNKNOWN - check speed/altitude etc to make decision as to what user is up to.
 760                                 } else {
 761                                         // HELP - we shouldn't ever get here!!!
 762                                 }
 763                         }
 764                 }
 765         }
 766         //cout << "Done CheckRunwayList" << endl;
 767 }
 768
 769 // Do one plane from the approach list
 770 void FGTower::CheckApproachList(double dt) {
 771         if(appList.size()) {
 772                 if(appListItr == appList.end()) {
 773                         appListItr = appList.begin();
 774                 }
 775                 TowerPlaneRec* t = *appListItr;
 776                 //cout << "t = " << t << endl;
 777                 if(t->isUser) {
 778                         t->pos.setlon(user_lon_node->getDoubleValue());
 779                         t->pos.setlat(user_lat_node->getDoubleValue());
 780                         t->pos.setelev(user_elev_node->getDoubleValue());
 781                 } else {
 782                         // TODO - set/update the position if it's an AI plane
 783                 }
 784                 if(t->nextOnRwy && !(t->clearedToLand)) {
 785                         // check distance away and whether runway occupied
 786                         // and schedule transmission if necessary
 787                 }
 788                 ++appListItr;
 789         }
 790 }
 791
 792 // Returns true if positions of crosswind/downwind/base leg turns should be constrained by previous traffic
 793 // plus the constraint position as a rwy orientated orthopos (meters)
 794 bool FGTower::GetCrosswindConstraint(double& cpos) {
 795         if(crosswind_leg_pos != 0.0) {
 796                 cpos = crosswind_leg_pos;
 797                 return(true);
 798         } else {
 799                 cpos = 0.0;
 800                 return(false);
 801         }
 802 }
 803 bool FGTower::GetDownwindConstraint(double& dpos) {
 804         if(downwind_leg_pos != 0.0) {
 805                 dpos = downwind_leg_pos;
 806                 return(true);
 807         } else {
 808                 dpos = 0.0;
 809                 return(false);
 810         }
 811 }
 812 bool FGTower::GetBaseConstraint(double& bpos) {
 813         if(base_leg_pos != 0.0) {
 814                 bpos = base_leg_pos;
 815                 return(true);
 816         } else {
 817                 bpos = 0.0;
 818                 return(false);
 819         }
 820 }
 821
 822
 823 // Figure out which runways are active.
 824 // For now we'll just be simple and do one active runway - eventually this will get much more complex
 825 // This is a private function - public interface to the results of this is through GetActiveRunway
 826 void FGTower::DoRwyDetails() {
 827         //cout << "GetRwyDetails called" << endl;
 828
 829         // Based on the airport-id and wind get the active runway
 830
 831         //wind
 832         double hdg = wind_from_hdg->getDoubleValue();
 833         double speed = wind_speed_knots->getDoubleValue();
 834         hdg = (speed == 0.0 ? 270.0 : hdg);
 835         //cout << "Heading = " << hdg << '\n';
 836
 837         FGRunway runway;
 838         bool rwyGood = globals->get_runways()->search(ident, int(hdg), &runway);
 839         if(rwyGood) {
 840                 activeRwy = runway.rwy_no;
 841                 rwy.rwyID = runway.rwy_no;
 842                 SG_LOG(SG_ATC, SG_INFO, "Active runway for airport " << ident << " is " << activeRwy);
 843
 844                 // Get the threshold position
 845                 double other_way = runway.heading - 180.0;
 846                 while(other_way <= 0.0) {
 847                         other_way += 360.0;
 848                 }
 849         // move to the +l end/center of the runway
 850                 //cout << "Runway center is at " << runway.lon << ", " << runway.lat << '\n';
 851         Point3D origin = Point3D(runway.lon, runway.lat, aptElev);
 852                 Point3D ref = origin;
 853         double tshlon, tshlat, tshr;
 854                 double tolon, tolat, tor;
 855                 rwy.length = runway.length * SG_FEET_TO_METER;
 856                 rwy.width = runway.width * SG_FEET_TO_METER;
 857         geo_direct_wgs_84 ( aptElev, ref.lat(), ref.lon(), other_way,
 858                                 rwy.length / 2.0 - 25.0, &tshlat, &tshlon, &tshr );
 859         geo_direct_wgs_84 ( aptElev, ref.lat(), ref.lon(), runway.heading,
 860                                 rwy.length / 2.0 - 25.0, &tolat, &tolon, &tor );
 861                 // Note - 25 meters in from the runway end is a bit of a hack to put the plane ahead of the user.
 862                 // now copy what we need out of runway into rwy
 863         rwy.threshold_pos = Point3D(tshlon, tshlat, aptElev);
 864                 Point3D takeoff_end = Point3D(tolon, tolat, aptElev);
 865                 //cout << "Threshold position = " << tshlon << ", " << tshlat << ", " << aptElev << '\n';
 866                 //cout << "Takeoff position = " << tolon << ", " << tolat << ", " << aptElev << '\n';
 867                 rwy.hdg = runway.heading;
 868                 // Set the projection for the local area based on this active runway
 869                 ortho.Init(rwy.threshold_pos, rwy.hdg);
 870                 rwy.end1ortho = ortho.ConvertToLocal(rwy.threshold_pos);        // should come out as zero
 871                 rwy.end2ortho = ortho.ConvertToLocal(takeoff_end);
 872         } else {
 873                 SG_LOG(SG_ATC, SG_ALERT, "Help  - can't get good runway in FGTower!!");
 874                 activeRwy = "NN";
 875         }
 876 }
 877
 878
 879 // Figure out if a given position lies on the active runway
 880 // Might have to change when we consider more than one active rwy.
 881 bool FGTower::OnActiveRunway(Point3D pt) {
 882         // TODO - check that the centre calculation below isn't confused by displaced thesholds etc.
 883         Point3D xyc((rwy.end1ortho.x() + rwy.end2ortho.x())/2.0, (rwy.end1ortho.y() + rwy.end2ortho.y())/2.0, 0.0);
 884         Point3D xyp = ortho.ConvertToLocal(pt);
 885
 886         //cout << "Length offset = " << fabs(xyp.y() - xyc.y()) << '\n';
 887         //cout << "Width offset = " << fabs(xyp.x() - xyc.x()) << '\n';
 888
 889         double rlen = rwy.length/2.0 + 5.0;
 890         double rwidth = rwy.width/2.0;
 891         double ldiff = fabs(xyp.y() - xyc.y());
 892         double wdiff = fabs(xyp.x() - xyc.x());
 893
 894         return((ldiff < rlen) && (wdiff < rwidth));
 895 }
 896
 897
 898 // Figure out if a given position lies on any runway or not
 899 // Only call this at startup - reading the runways database is expensive and needs to be fixed!
 900 bool FGTower::OnAnyRunway(Point3D pt) {
 901         ATCData ad;
 902         double dist = current_commlist->FindClosest(lon, lat, elev, ad, TOWER, 10.0);
 903         if(dist < 0.0) {
 904                 return(false);
 905         }
 906         // Based on the airport-id, go through all the runways and check for a point in them
 907
 908         // TODO - do we actually need to search for the airport - surely we already know our ident and
 909         // can just search runways of our airport???
 910         //cout << "Airport ident is " << ad.ident << '\n';
 911         FGRunway runway;
 912         bool rwyGood = globals->get_runways()->search(ad.ident, &runway);
 913         if(!rwyGood) {
 914                 SG_LOG(SG_ATC, SG_WARN, "Unable to find any runways for airport ID " << ad.ident << " in FGTower");
 915         }
 916         bool on = false;
 917         while(runway.id == ad.ident) {
 918                 on = OnRunway(pt, runway);
 919                 //cout << "Runway " << runway.rwy_no << ": On = " << (on ? "true\n" : "false\n");
 920                 if(on) return(true);
 921                 globals->get_runways()->next(&runway);
 922         }
 923         return(on);
 924 }
 925
 926
 927 // Returns true if successful
 928 bool FGTower::RemoveFromTrafficList(string id) {
 929         tower_plane_rec_list_iterator twrItr;
 930         for(twrItr = trafficList.begin(); twrItr != trafficList.end(); twrItr++) {
 931                 TowerPlaneRec* tpr = *twrItr;
 932                 if(tpr->plane.callsign == id) {
 933                         trafficList.erase(twrItr);
 934                         return(true);
 935                 }
 936         }
 937         SG_LOG(SG_ATC, SG_WARN, "Warning - unable to remove aircraft " << id << " from trafficList in FGTower");
 938         return(false);
 939 }
 940
 941
 942 // Add a tower plane rec with ETA to the traffic list in the correct position ETA-wise
 943 // and set nextOnRwy if so.
 944 // Returns true if this could cause a threshold ETA conflict with other traffic, false otherwise.
 945 // For planes holding they are put in the first position with time to go, and the return value is
 946 // true if in the first position (nextOnRwy) and false otherwise.
 947 // See the comments in FGTower::doThresholdUseOrder for notes on the ordering
 948 bool FGTower::AddToTrafficList(TowerPlaneRec* t, bool holding) {
 949         //cout << "ADD: " << trafficList.size();
 950         //cout << "AddToTrafficList called, currently size = " << trafficList.size() << ", holding = " << holding << endl;
 951         double separation_time = 90.0;  // seconds - this is currently a guess for light plane separation, and includes a few seconds for a holding plane to taxi onto the rwy.
 952         double departure_sep_time = 60.0;       // Separation time behind departing airplanes.  Comments above also apply.
 953         bool conflict = false;
 954         double lastETA = 0.0;
 955         bool firstTime = true;
 956         // FIXME - make this more robust for different plane types eg. light following heavy.
 957         tower_plane_rec_list_iterator twrItr;
 958         //twrItr = trafficList.begin();
 959         //while(1) {
 960         for(twrItr = trafficList.begin(); twrItr != trafficList.end(); twrItr++) {
 961                 //if(twrItr == trafficList.end()) {
 962                 //      cout << "  END  ";
 963                 //      trafficList.push_back(t);
 964                 //      return(holding ? firstTime : conflict);
 965                 //} else {
 966                         TowerPlaneRec* tpr = *twrItr;
 967                         if(holding) {
 968                                 //cout << (tpr->isUser ? "USER!\n" : "NOT user\n");
 969                                 //cout << "tpr->eta - lastETA = " << tpr->eta - lastETA << '\n';
 970                                 double dep_allowance = (timeSinceLastDeparture < departure_sep_time ? departure_sep_time - timeSinceLastDeparture : 0.0);
 971                                 double slot_time = (firstTime ? separation_time + dep_allowance : separation_time + departure_sep_time);
 972                                 // separation_time + departure_sep_time in the above accounts for the fact that the arrival could be touch and go,
 973                                 // and if not needs time to clear the rwy anyway.
 974                                 if(tpr->eta  - lastETA > slot_time) {
 975                                         t->nextOnRwy = firstTime;
 976                                         trafficList.insert(twrItr, t);
 977                                         //cout << "\tH\t" << trafficList.size() << '\n';
 978                                         return(firstTime);
 979                                 }
 980                                 firstTime = false;
 981                         } else {
 982                                 if(t->eta < tpr->eta) {
 983                                         // Ugg - this one's tricky.
 984                                         // It depends on what the two planes are doing and whether there's a conflict what we do.
 985                                         if(tpr->eta - t->eta > separation_time) {       // No probs, plane 2 can squeeze in before plane 1 with no apparent conflict
 986                                                 if(tpr->nextOnRwy) {
 987                                                         tpr->nextOnRwy = false;
 988                                                         t->nextOnRwy = true;
 989                                                 }
 990                                                 trafficList.insert(twrItr, t);
 991                                         } else {        // Ooops - this ones tricky - we have a potential conflict!
 992                                                 conflict = true;
 993                                                 // HACK - just add anyway for now and flag conflict - TODO - FIX THIS using CIRCUIT/STRAIGHT_IN and VFR/IFR precedence rules.
 994                                                 if(tpr->nextOnRwy) {
 995                                                         tpr->nextOnRwy = false;
 996                                                         t->nextOnRwy = true;
 997                                                 }
 998                                                 trafficList.insert(twrItr, t);
 999                                         }
1000                                         //cout << "\tC\t" << trafficList.size() << '\n';
1001                                         return(conflict);
1002                                 }
1003                         }
1004                 //}
1005                 //++twrItr;
1006         }
1007         // If we get here we must be at the end of the list, or maybe the list is empty.
1008         if(!trafficList.size()) {
1009                 t->nextOnRwy = true;
1010                 // conflict and firstTime should be false and true respectively in this case anyway.
1011         }
1012         trafficList.push_back(t);
1013         //cout << "\tE\t" << trafficList.size() << endl;
1014         return(holding ? firstTime : conflict);
1015 }
1016
1017
1018 // Calculate the eta of a plane to the threshold.
1019 // For ground traffic this is the fastest they can get there.
1020 // For air traffic this is the middle approximation.
1021 void FGTower::CalcETA(TowerPlaneRec* tpr, bool printout) {
1022         // For now we'll be very crude and hardwire expected speeds to C172-like values
1023         // The speeds below are specified in knots IAS and then converted to m/s
1024         double app_ias = 100.0 * 0.514444;                      // Speed during straight-in approach
1025         double circuit_ias = 80.0 * 0.514444;           // Speed around circuit
1026         double final_ias = 70.0 * 0.514444;             // Speed during final approach
1027
1028         //if(printout) {
1029         //cout << "In CalcETA, airplane ident = " << tpr->plane.callsign << '\n';
1030         //cout << (tpr->isUser ? "USER\n" : "AI\n");
1031         //cout << flush;
1032         //}
1033
1034         // Sign convention - dist_out is -ve for approaching planes and +ve for departing planes
1035         // dist_across is +ve in the pattern direction - ie a plane correctly on downwind will have a +ve dist_across
1036
1037         Point3D op = ortho.ConvertToLocal(tpr->pos);
1038         //if(printout) {
1039         //      cout << "Orthopos is " << op.x() << ", " << op.y() << '\n';
1040         //      cout << "opType is " << tpr->opType << '\n';
1041         //}
1042         double dist_out_m = op.y();
1043         double dist_across_m = fabs(op.x());    // FIXME = the fabs is a hack to cope with the fact that we don't know the circuit direction yet
1044         //cout << "Doing ETA calc for " << tpr->plane.callsign << '\n';
1045
1046         if(tpr->opType == STRAIGHT_IN) {
1047                 double dist_to_go_m = sqrt((dist_out_m * dist_out_m) + (dist_across_m * dist_across_m));
1048                 if(dist_to_go_m < 1000) {
1049                         tpr->eta = dist_to_go_m / final_ias;
1050                 } else {
1051                         tpr->eta = (1000.0 / final_ias) + ((dist_to_go_m - 1000.0) / app_ias);
1052                 }
1053         } else if(tpr->opType == CIRCUIT || tpr->opType == TTT_UNKNOWN) {       // Hack alert - UNKNOWN has sort of been added here as a temporary hack.
1054                 // It's complicated - depends on if base leg is delayed or not
1055                 //if(printout) {
1056                 //      cout << "Leg = " << tpr->leg << '\n';
1057                 //}
1058                 if(tpr->leg == LANDING_ROLL) {
1059                         tpr->eta = 0;
1060                 } else if((tpr->leg == FINAL) || (tpr->leg == TURN4)) {
1061                         tpr->eta = fabs(dist_out_m) / final_ias;
1062                 } else if((tpr->leg == BASE) || (tpr->leg == TURN3)) {
1063                         tpr->eta = (fabs(dist_out_m) / final_ias) + (dist_across_m / circuit_ias);
1064                 } else {
1065                         // Need to calculate where base leg is likely to be
1066                         // FIXME - for now I'll hardwire it to 1000m which is what AILocalTraffic uses!!!
1067                         // TODO - as a matter of design - AILocalTraffic should get the nominal no-traffic base turn distance from Tower, since in real life the published pattern might differ from airport to airport
1068                         double nominal_base_dist_out_m = -1000;
1069                         double current_base_dist_out_m;
1070                         if(!GetBaseConstraint(current_base_dist_out_m)) {
1071                                 current_base_dist_out_m = nominal_base_dist_out_m;
1072                         }
1073                         double nominal_dist_across_m = 1000;    // Hardwired value from AILocalTraffic
1074                         double current_dist_across_m;
1075                         if(!GetDownwindConstraint(current_dist_across_m)) {
1076                                 current_dist_across_m = nominal_dist_across_m;
1077                         }
1078                         double nominal_cross_dist_out_m = 2000; // Bit of a guess - AI plane turns to crosswind at 600ft agl.
1079                         tpr->eta = fabs(current_base_dist_out_m) / final_ias;   // final
1080                         //if(printout) cout << "a = " << tpr->eta << '\n';
1081                         if((tpr->leg == DOWNWIND) || (tpr->leg == TURN2)) {
1082                                 tpr->eta += dist_across_m / circuit_ias;
1083                                 //if(printout) cout << "b = " << tpr->eta << '\n';
1084                                 tpr->eta += fabs(current_base_dist_out_m - dist_out_m) / circuit_ias;
1085                                 //if(printout) cout << "c = " << tpr->eta << '\n';
1086                         } else if((tpr->leg == CROSSWIND) || (tpr->leg == TURN1)) {
1087                                 if(dist_across_m > nominal_dist_across_m) {
1088                                         tpr->eta += dist_across_m / circuit_ias;
1089                                 } else {
1090                                         tpr->eta += nominal_dist_across_m / circuit_ias;
1091                                 }
1092                                 // should we use the dist across of the previous plane if there is previous still on downwind?
1093                                 //if(printout) cout << "bb = " << tpr->eta << '\n';
1094                                 if(dist_out_m > nominal_cross_dist_out_m) {
1095                                         tpr->eta += fabs(current_base_dist_out_m - dist_out_m) / circuit_ias;
1096                                 } else {
1097                                         tpr->eta += fabs(current_base_dist_out_m - nominal_cross_dist_out_m) / circuit_ias;
1098                                 }
1099                                 //if(printout) cout << "cc = " << tpr->eta << '\n';
1100                                 if(nominal_dist_across_m > dist_across_m) {
1101                                         tpr->eta += (nominal_dist_across_m - dist_across_m) / circuit_ias;
1102                                 } else {
1103                                         // Nothing to add
1104                                 }
1105                                 //if(printout) cout << "dd = " << tpr->eta << '\n';
1106                         } else {
1107                                 // We've only just started - why not use a generic estimate?
1108                                 tpr->eta = 240.0;
1109                         }
1110                 }
1111                 //if(printout) {
1112                 //      cout << "ETA = " << tpr->eta << '\n';
1113                 //}
1114         } else {
1115                 tpr->eta = 99999;
1116         }
1117 }
1118
1119
1120 // Calculate the distance of a plane to the threshold in meters
1121 // TODO - Modify to calculate flying distance of a plane in the circuit
1122 double FGTower::CalcDistOutM(TowerPlaneRec* tpr) {
1123         return(dclGetHorizontalSeparation(rwy.threshold_pos, tpr->pos));
1124 }
1125
1126
1127 // Calculate the distance of a plane to the threshold in miles
1128 // TODO - Modify to calculate flying distance of a plane in the circuit
1129 double FGTower::CalcDistOutMiles(TowerPlaneRec* tpr) {
1130         return(CalcDistOutM(tpr) / 1600.0);             // FIXME - use a proper constant if possible.
1131 }
1132
1133
1134 // Iterate through all the lists and call CalcETA for all the planes.
1135 void FGTower::doThresholdETACalc() {
1136         //cout << "Entering doThresholdETACalc..." << endl;
1137         tower_plane_rec_list_iterator twrItr;
1138         // Do the approach list first
1139         for(twrItr = appList.begin(); twrItr != appList.end(); twrItr++) {
1140                 TowerPlaneRec* tpr = *twrItr;
1141                 CalcETA(tpr);
1142         }
1143         // Then the circuit list
1144         for(twrItr = circuitList.begin(); twrItr != circuitList.end(); twrItr++) {
1145                 TowerPlaneRec* tpr = *twrItr;
1146                 CalcETA(tpr);
1147         }
1148         //cout << "Done doThresholdETCCalc" << endl;
1149 }
1150
1151
1152 // Check that the planes in traffic list are correctly ordered,
1153 // that the nearest (timewise) is flagged next on rwy, and return
1154 // true if any threshold use conflicts are detected, false otherwise.
1155 bool FGTower::doThresholdUseOrder() {
1156         //cout << "Entering doThresholdUseOrder..." << endl;
1157         bool conflict = false;
1158
1159         // Wipe out traffic list, go through circuit, app and hold list, and reorder them in traffic list.
1160         // Here's the rather simplistic assumptions we're using:
1161         // Currently all planes are assumed to be GA light singles with corresponding speeds and separation times.
1162         // In order of priority for runway use:
1163         // STRAIGHT_IN > CIRCUIT > HOLDING_FOR_DEPARTURE
1164         // No modification of planes speeds occurs - conflicts are resolved by delaying turn for base,
1165         // and holding planes until a space.
1166         // When calculating if a holding plane can use the runway, time clearance from last departure
1167         // as well as time clearance to next arrival must be considered.
1168
1169         trafficList.clear();
1170
1171         tower_plane_rec_list_iterator twrItr;
1172         // Do the approach list first
1173         //cout << "A" << flush;
1174         for(twrItr = appList.begin(); twrItr != appList.end(); twrItr++) {
1175                 TowerPlaneRec* tpr = *twrItr;
1176                 conflict = AddToTrafficList(tpr);
1177         }
1178         // Then the circuit list
1179         //cout << "C" << flush;
1180         for(twrItr = circuitList.begin(); twrItr != circuitList.end(); twrItr++) {
1181                 TowerPlaneRec* tpr = *twrItr;
1182                 conflict = AddToTrafficList(tpr);
1183         }
1184         // And finally the hold list
1185         //cout << "H" << endl;
1186         for(twrItr = holdList.begin(); twrItr != holdList.end(); twrItr++) {
1187                 TowerPlaneRec* tpr = *twrItr;
1188                 AddToTrafficList(tpr, true);
1189         }
1190
1191         if(0) {
1192         //if(ident == "KEMT") {
1193                 for(twrItr = trafficList.begin(); twrItr != trafficList.end(); twrItr++) {
1194                         TowerPlaneRec* tpr = *twrItr;
1195                         cout << tpr->plane.callsign << '\t' << tpr->eta << '\t';
1196                 }
1197                 cout << endl;
1198         }
1199
1200         //cout << "Done doThresholdUseOrder" << endl;
1201         return(conflict);
1202 }
1203
1204
1205 // Return the ETA of plane no. list_pos (1-based) in the traffic list.
1206 // i.e. list_pos = 1 implies next to use runway.
1207 double FGTower::GetTrafficETA(unsigned int list_pos, bool printout) {
1208         if(trafficList.size() < list_pos) {
1209                 return(99999);
1210         }
1211
1212         tower_plane_rec_list_iterator twrItr;
1213         twrItr = trafficList.begin();
1214         for(unsigned int i = 1; i < list_pos; i++, twrItr++);
1215         TowerPlaneRec* tpr = *twrItr;
1216         CalcETA(tpr, printout);
1217         //cout << "ETA returned = " << tpr->eta << '\n';
1218         return(tpr->eta);
1219 }
1220
1221
1222 void FGTower::ContactAtHoldShort(PlaneRec plane, FGAIPlane* requestee, tower_traffic_type operation) {
1223         // HACK - assume that anything contacting at hold short is new for now - FIXME LATER
1224         TowerPlaneRec* t = new TowerPlaneRec;
1225         t->plane = plane;
1226         t->planePtr = requestee;
1227         t->holdShortReported = true;
1228         t->clearanceCounter = 0;
1229         t->clearedToLineUp = false;
1230         t->clearedToTakeOff = false;
1231         t->opType = operation;
1232
1233         //cout << "Hold Short reported by " << plane.callsign << '\n';
1234
1235 /*
1236         bool next = AddToTrafficList(t, true);
1237         if(next) {
1238                 double teta = GetTrafficETA(2);
1239                 if(teta < 150.0) {
1240                         t->clearanceCounter = 7.0;      // This reduces the delay before response to 3 secs if an immediate takeoff is reqd
1241                         //cout << "Reducing response time to request due imminent traffic\n";
1242                 }
1243         } else {
1244         }
1245 */
1246         // TODO - possibly add the reduced interval to clearance when immediate back in under the new scheme
1247
1248         holdList.push_back(t);
1249
1250         responseReqd = true;
1251 }
1252
1253 void FGTower::RequestLandingClearance(string ID) {
1254         //cout << "Request Landing Clearance called...\n";
1255
1256         // Assume this comes from the user - have another function taking a pointer to the AIplane for the AI traffic.
1257         // For now we'll also assume that the user is a light plane and can get him/her to join the circuit if necessary.
1258
1259         TowerPlaneRec* t = new TowerPlaneRec;
1260         t->isUser = true;
1261         t->clearedToLand = false;
1262         t->pos.setlon(user_lon_node->getDoubleValue());
1263         t->pos.setlat(user_lat_node->getDoubleValue());
1264         t->pos.setelev(user_elev_node->getDoubleValue());
1265
1266         // TODO
1267         // Calculate where the user is in relation to the active runway and it's circuit
1268         // and set the op-type as appropriate.
1269
1270         // HACK - to get up and running I'm going to assume that the user contacts tower on a staight-in final for now.
1271         t->opType = STRAIGHT_IN;
1272
1273         t->plane.type = GA_SINGLE;      // FIXME - Another assumption!
1274         t->plane.callsign = ID;
1275
1276         appList.push_back(t);   // Not necessarily permanent
1277         AddToTrafficList(t);
1278 }
1279
1280 void FGTower::RequestDepartureClearance(string ID) {
1281         //cout << "Request Departure Clearance called...\n";
1282 }
1283 //void FGTower::ReportFinal(string ID);
1284 //void FGTower::ReportLongFinal(string ID);
1285 //void FGTower::ReportOuterMarker(string ID);
1286 //void FGTower::ReportMiddleMarker(string ID);
1287 //void FGTower::ReportInnerMarker(string ID);
1288 //void FGTower::ReportGoingAround(string ID);
1289 void FGTower::ReportRunwayVacated(string ID) {
1290         //cout << "Report Runway Vacated Called...\n";
1291 }
1292
1293 TowerPlaneRec* FGTower::FindPlane(string ID) {
1294         tower_plane_rec_list_iterator twrItr;
1295         // Do the approach list first
1296         for(twrItr = appList.begin(); twrItr != appList.end(); twrItr++) {
1297                 if((*twrItr)->plane.callsign == ID) return(*twrItr);
1298         }
1299         // Then the circuit list
1300         for(twrItr = circuitList.begin(); twrItr != circuitList.end(); twrItr++) {
1301                 if((*twrItr)->plane.callsign == ID) return(*twrItr);
1302         }
1303         // And finally the hold list
1304         for(twrItr = holdList.begin(); twrItr != holdList.end(); twrItr++) {
1305                 if((*twrItr)->plane.callsign == ID) return(*twrItr);
1306         }
1307         SG_LOG(SG_ATC, SG_WARN, "Unable to find " << ID << " in FGTower::FindPlane(...)");
1308         return(NULL);
1309 }
1310
1311 void FGTower::ReportDownwind(string ID) {
1312         //cout << "ReportDownwind(...) called\n";
1313         // Tell the plane reporting what number she is in the circuit
1314         TowerPlaneRec* t = FindPlane(ID);
1315         if(t) {
1316                 t->downwindReported = true;
1317                 responseReqd = true;
1318         } else {
1319                 SG_LOG(SG_ATC, SG_WARN, "WARNING: Unable to find plane " << ID << " in FGTower::ReportDownwind(...)");
1320         }
1321 }
1322
1323 ostream& operator << (ostream& os, tower_traffic_type ttt) {
1324         switch(ttt) {
1325         case(CIRCUIT):      return(os << "CIRCUIT");
1326         case(INBOUND):      return(os << "INBOUND");
1327         case(OUTBOUND):     return(os << "OUTBOUND");
1328         case(TTT_UNKNOWN):  return(os << "UNKNOWN");
1329         case(STRAIGHT_IN):  return(os << "STRAIGHT_IN");
1330         }
1331         return(os << "ERROR - Unknown switch in tower_traffic_type operator << ");
1332 }
1333